Other changes

The default character set for htmlspecialchars()
and htmlentities() is now UTF-8,
instead of ISO-8859-1. Note that changing your output
charset via the default_charset
configuration setting does not affect htmlspecialchars/htmlentities unless
you are passing "" (an empty string) as the encoding parameter to your
htmlspecialchars()/htmlentities() calls.
Generally we do not recommend doing this because you should be able to
change your output charset without affecting the runtime charset used by
these functions. The safest approach is to explicitly set the charset on
each call to htmlspecialchars() and
htmlentities().

E_ALL now includes E_STRICT level
errors in the error_reporting configuration directive.

SNMP now has an OOP API.
Functions now return FALSE on every error condition including SNMP-related
(no such instance, end of MIB, etc). Thus, in particular, breaks previous behavior
of get/walk functions returning an empty string on SNMP-related errors.
Multi OID get/getnext/set queries are now supported.
Dropped UCD-SNMP compatibility code, consider upgrading to net-snmp v5.3+, Net-SNMP v5.4+ is
required for Windows version.
In sake of adding support for IPv6 DNS name resolution of
remote SNMP agent (peer) is done by extension now, not by Net-SNMP library anymore.